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Image Processing
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| license: gpl-3.0 |
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| (function() { | |
| var po = org.polymaps; | |
| po.canvas = function() { | |
| var canvas = po.layer(load, unload), | |
| image = po.svg("image"), // dummy image | |
| url; | |
| function load(tile) { | |
| var size = canvas.map().tileSize(), | |
| o = tile.element = po.svg("foreignObject"), | |
| c = o.appendChild(document.createElement("canvas")), | |
| w = size.x, | |
| h = size.y; | |
| o.setAttribute("width", w); | |
| o.setAttribute("height", h); | |
| c.setAttribute("width", w); | |
| c.setAttribute("height", h); | |
| tile.request = po.queue.image(image, url(tile), function(img) { | |
| var g = c.getContext("2d"), | |
| d = g.createImageData(w, h), | |
| e; | |
| delete tile.request; | |
| tile.ready = true; | |
| g.drawImage(img, 0, 0); | |
| e = g.getImageData(0, 0, w, h); | |
| for (var i = 0, n = w * h * 4; i < n; i++) d.data[i] = e.data[i] / 2; // e.g. | |
| g.putImageData(d, 0, 0); | |
| canvas.dispatch({type: "load", tile: tile}); | |
| }); | |
| } | |
| function unload(tile) { | |
| if (tile.request) tile.request.abort(true); | |
| } | |
| canvas.url = function(x) { | |
| if (!arguments.length) return url; | |
| url = po.url(x); | |
| return canvas.reload(); | |
| }; | |
| return canvas; | |
| }; | |
| })(); |
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <script type="text/javascript" src="https://cdn.rawgit.com/simplegeo/polymaps/v2.3.0/polymaps.min.js"></script> | |
| <script type="text/javascript" src="canvas.js"></script> | |
| <style type="text/css"> | |
| @import url("https://cdn.rawgit.com/simplegeo/polymaps/v2.3.0/examples/example.css"); | |
| </style> | |
| </head> | |
| <body> | |
| <script type="text/javascript"> | |
| var po = org.polymaps; | |
| var map = po.map() | |
| .container(document.body.appendChild(po.svg("svg"))) | |
| .tileSize({x: 149, y: 149}) | |
| .add(po.interact()); | |
| map.add(po.canvas() | |
| .url("http://bl.ocks.org/forkme.png")); | |
| map.add(po.compass() | |
| .pan("none")); | |
| </script> | |
| </body> | |
| </html> |
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Please replace the polymaps reference to this: https://cdnjs.cloudflare.com/ajax/libs/polymaps/2.3.0/polymaps.min.js
Because now the example is not working (because of MIME type text/plain)